Laser emitting diodes have come into widespread usage as a result of their advantages, which include their small size, long life, low energy consumption, and low heat generation. Set against this background, there are high expectations for illuminating devices, such as those using laser emitting diodes capable of emitting visible light having a uniform luminance distribution throughout a large display area. However, conventional illuminating devices are not necessarily satisfactory due to their unevenness in luminance distribution.